Functional studies of the role of plant dehydrins in tolerance to salinity, desiccation and

Dehydrins are a group of proteins believed to play a fundamental role in plant response and adaptation to abiotic stresses that lead to cellular dehydration. This group of proteins can be found in seeds in the later maturation stage and the desiccated seed, and are induced by salt, drought and low temperature stress. Dehydrins share no sequence homology with any known protein or enzyme and have so far only been found in photosynthesizing organisms. We have purified four recombinant dehydrins (RAB18, LTI29, LTI30 and COR47) and introduce a method previously not used for purification of dehydrins; immobilized metal ion affinity chromatography. Furthermore the accumulation of both transcript and protein was analyzed for five dehydrins (ERD14, RAB18, LTI29, LTI30 and COR47). Based on the accumulation data the dehydrins could be divided into four groups: (I) LTI30 cold specific, (II) RAB18 ABA regulated, (III) ERD14 constitutive and (IIII) LTI29 and COR47 mainly cold induced. Immunolocalization studies of four dehydrins (ERD14, LTI29, LTI30 and RAB18) showed tissue and cell type specific accumulation in unstressed plants. ERD14 and LTI29 were detected in the root tip and the vascular tissue whereas RAB18 was detected in stomatal guard cells. LTI30 was not detected in unstressed plants. In stress treated plants RAB18, LTI29 and ERD14 were detected in most cells whereas LTI30 was only detected in the vascular tissue and in pollen sacks. Ectopic expression of multiple dehydrins in Arabidopsis resulted in improved survival of plants exposed to drought and freezing stress. In addition, salt stressed seeds overproducing DHNs showed improved germination/cotyledon emergence. We isolated a dehydrin gene (DHNA) from Physcomitrella patens which shared some characteristics of dehydrins cloned in higher plants. DHNA was found to be expressed during salt and water stress and by ABA treatm

Author

• Jan Svensson

• plant physiology
• stress
• frost
• cold
• dehydration
• adaptation
• aba
• proteins
• temperature resistance
• gene expression
• dehydrins
• low temperature
• drought
• salinity
• protein purification
• Arabidopsis
• Physcomitrella patens

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https://pub.epsilon.slu.se/24/

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oai:pub.epsilon.slu.se:24